When Akihiko Kondo, a 35-year-old school administrator in Tokyo, strolled down the aisle in a white tuxedo in November, his mother was not among the 40 well-wishers in attendance. For her, he said, “it was not something to celebrate.”

You might see why. The bride, a songstress with aquamarine twin tails named Hatsune Miku, is not only a world-famous recording artist who fills up arenas throughout Japan: She is also a hologram.

Mr. Kondo insists the wedding was not a stunt, but a triumph of true love after years of feeling ostracized by real-life women for being an anime otaku, or geek.